scholarly journals Understanding the high temperature side of the hot ductility curve for steels

2021 ◽  
pp. 1-13
Author(s):  
B. Mintz ◽  
A. Qaban
Keyword(s):  
High Temperature ◽  
Hot Ductility ◽  
High Temperature Side ◽  
Temperature Side

Search for High Damping Metallic Glasses

2006 ◽  
Vol 319 ◽  
pp. 151-156 ◽  
Author(s):  
Y. Hiki ◽  
M. Tanahashi ◽  
Shin Takeuchi
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Internal Friction ◽  
Metallic Glass ◽  
Room Temperature ◽  
Temperature Stability ◽  
Temperature Peak ◽  
High Temperature Side ◽  
Side Slope ◽  
Temperature Side

In a hydrogen-doped metallic glass, there appear low-temperature and high-temperature internal friction peaks respectively associated with a point-defect relaxation and the crystallization. The high-temperature-side slope of low-temperature peak and also the low-temperature-side slope of high-temperature peak enhance the background internal friction near the room temperature. A hydrogen-doped Mg-base metallic glass was proposed as a high-damping material to be used near and somewhat above the room temperature. Stability of the high damping was also checked.

Tourmaline and boron as indicators of the presence, segregation and extraction of melt in pelitic migmatites: examples from the Ryoke metamorphic belt, SW Japan

2004 ◽  
Vol 95 (1-2) ◽  
pp. 111-123 ◽  
Author(s):  
Tetsuo Kawakami
Keyword(s):  
High Temperature ◽  
Partial Melting ◽  
Correct Recognition ◽  
High Temperature Side ◽  
Metamorphic Belt ◽  
Melt Extraction ◽  
Mode Of Occurrence ◽  
Temperature Side ◽  
Sw Japan

The mode of occurrence of borosilicates and the breakdown fronts of prograde tourmaline (tourmaline-out isograd) in three anatectic migmatite regions of the Ryoke metamorphic belt, SW Japan, are reported. The breakdown of tourmaline in the migmatite zones and release of boron into the melts, followed by the extraction of the boron-bearing melts from the migmatite zones occurred throughout the Ryoke metamorphic belt. Retrograde, magmatic tourmaline in interboudin partitions filled with leucosome is useful for calculating the degree of partial melting in the migmatites. Using boron contents in the leucosomes and pelitic schists, the degree of partial melting at the migmatite front of the Aoyama area is estimated to be 12 wt.%. Extraction of the boron-bearing melt is suggested by the boron-depleted nature of the migmatites. Connection of boudinage structures probably supplied the vertical pathways of the segregated melts, and major transport of the melts was accomplished by dyking. Irregularly shaped, amoeboid tourmaline locally occurs on the high-temperature side of the tourmaline-out isograds in the Yanai and Komagane areas, implying incomplete extraction of boron-bearing melts from those areas. Discriminating retrograde from prograde tourmaline enables correct recognition of the tourmaline-out isograd. The amount of retrograde tourmaline in migmatites can potentially be used as an indicator of the degree of melt extraction from them.

SPECIFIC HEAT ANOMALY FOR H ≥ 28.5 T IN CeIrIn5

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3014-3017
Author(s):  
J. S. KIM ◽  
J. ALWOOD ◽  
P. KUMAR ◽  
G. R. STEWART
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Specific Heat ◽  
Single Crystals ◽  
Hybrid Magnet ◽  
High Temperature Side ◽  
And Shifts ◽  
Temperature Side

Recently Takeuchi reported a weak, 'metamagnetic-like' increase in the magnetization around 42 T in single crystals of CeIrIn 5 for field in the c-direction. We report specific heat measurements on single crystal CeIrIn 5, H parallel c-axis, measured in the dc hybrid magnet at NHMFL in Tallahassee between 1.4 and 10 K. A clear anomaly in C/T in 35 T is observed to peak at 1.8 K, with an entropy of 6% of RIn2. This anomaly grows in size and shifts upwards in temperature (both monotonically) with increasing H until at 45 T T peak =4.1 K , with the entropy associated with the transition equal to 14% of RIn2. C/T data at 32 T show3 only the high temperature side of the peak occurring above 1.4 K, while C/T data at 28.5 T show no anomaly down to 1.4 K. This is consistent with our Tpeak vs H data, which imply T peak → 0 at 26 T.

Development of the High Performance Thermoelectric Modules for High Temperature Heat Sources

2007 ◽  
Vol 534-536 ◽  
pp. 1521-1524 ◽  
Author(s):  
Takahiro Jinushi ◽  
Masahiro Okahara ◽  
Zenzo Ishijima ◽  
Hideo Shikata ◽  
Mitsuru Kambe
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Waste Heat ◽  
Module Structure ◽  
High Temperature Side ◽  
Powder Metallurgy Process ◽  
Stress Diffusion ◽  
Carbon Sheet ◽  
Metallurgy Process ◽  
Temperature Side

In recent years, power generating systems using thermoelectric elements have become attractive as an effective method of using industrial waste heat, at a temperature of around 773K, to produce energy. However, in order to develop a module usable under such a high temperature, certain concerns have to be overcome, e.g. thermal stress, diffusion of the connecting interfaces, etc. In this research, using an FeSi2 with diffusion barrier layers and a SiGe element produced by a powder metallurgy process, the module structure and installation method were optimized for application in PM sintering furnaces. As a result, from a viewpoint of heat stress at high temperatures and contact thermal resistance, it is confirmed that the optimal structure is the skeleton structure using Cu substrate on the cooling side, which has excellent heat conductivity and the optimal installation method is to adopt a carbon sheet and a mica sheet to the high temperature side, where Si grease is applied to the low temperature side, under pressurized condition. The power of the developed modules indicated 0.5W in an FeSi2 module and 3.8 W with a SiGe module at 827K, respectively. Moreover, neither breakage nor deterioration were observed after 30 heat cycles test simulating sintering furnace.

Notizen: Interpretation of the Hopkinson Secondary Maximum in Terms of Parallel Pumping Theory

1971 ◽  
Vol 26 (10) ◽  
pp. 1764-1766
Author(s):  
H. Markert
Keyword(s):  
Magnetic Field ◽  
High Temperature ◽  
High Frequency ◽  
Resonance Phenomenon ◽  
High Temperature Side ◽  
Dc Magnetic Field ◽  
Secondary Maximum ◽  
Ac Field ◽  
Measuring Signal ◽  
Temperature Side

AbstractSome former measurements are reviewed concerning a secondary maximum occurring at the high-temperature side of the usual Hopkinson peak if a dc-magnetic field is superimposed parallel to the ac-field. Since, with regard to single domain particles embedded in a paramagnetic matrix, the measuring signal is proportional to the high-frequency losses, a secondary maximum indicates some kind of resonance phenomenon which obviously fulfills the geometrical conditions of parallel pumping experiments. It is shown that all other aspects of the experimental results also can be explained sufficiently if being interpreted in terms of parallel pumping theory.

A Study on Influence of Annealing and Aging on High Temperature Internal Friction in Al-Zr Alloy

2012 ◽  
Vol 535-537 ◽  
pp. 1027-1030
Author(s):  
Xiao Hui Cao ◽  
Yu Wang
Keyword(s):  
High Temperature ◽  
Internal Friction ◽  
Grain Boundary ◽  
Low Frequency ◽  
Grain Boundary Sliding ◽  
High Temperature Side ◽  
Internal Friction Peak ◽  
Average Grain Size ◽  
Lower Temperature ◽  
Zr Alloy

By using a low frequency inverted torsion pendulum, the high temperature internal friction spectra of Al-0.02wt%Zr and Al-0.1wt%Zr alloys were investigated respectively. In Al-0.02wt%Zr alloy, the conventional grain boundary internal friction peak (Pg) is observed with some small unstable peaks. In Al-0.1wt%Zr alloy, the bamboo peak is observed to appear at the high temperature side of the conventional grain boundary internal friction peak. The conventional grain boundary internal friction peak decreased and moved to higher temperature. The bamboo peak owns an activation energy of 1.75eV. When average grain size exceeded the diameter of samples, Pb strength was reduced and its position was shifted to a lower temperature. Based on the grain boundary sliding model, Pg and Pb peaks were explained. Their dependence on annealing temperature and time was determined by considering the effects of contained Ce atoms and other impurities on the relaxation across grain boundary.

Moisture-dependent orthotropic viscoelastic properties of Chinese fir wood during quenching in the temperature range of 20 to −120°C

Holzforschung ◽  
2019 ◽  
Vol 74 (1) ◽  
pp. 10-19 ◽  
Author(s):  
Zhu Li ◽  
Jiali Jiang ◽  
Jianxiong Lyu
Keyword(s):  
Cell Wall ◽  
Viscoelastic Properties ◽  
Wood Cell Wall ◽  
Bound Water ◽  
Free Water ◽  
Chinese Fir ◽  
High Temperature Side ◽  
Temperature Spectrum ◽  
Β Relaxation ◽  
Temperature Side

AbstractAn understanding of wood’s moisture-dependent viscoelastic properties under various temperature conditions is important for assessing its utilization and product quality. In this study, we investigated the influence of moisture content (MC) on the orthotropic viscoelasticity of Chinese fir wood (Cunninghamia lanceolata [Lamb.] Hook.) during quenching ranging from 20 to −120°C. The storage modulus (E′) and loss factor (tan δ) of the longitudinal (L), radial (R) and tangential (T) specimens were determined for nine MC levels ranging from 0.6 to 60.0%. The results showed that E′ generally decreased with increasing amount of bound water in all orthotropic directions, regardless of the temperature. In contrast, a sharp increase in E′ was observed at temperatures below 0°C when free water was present, due to the formation of ice within the cell lumens. The γ-relaxation and β-relaxation were observed in the temperature spectrum. A comparison demonstrates that the β-relaxation showed evident grain orientation. When only bound water was present in the wood cell wall, one clear γ-relaxation was found for all orthotropic directions. In contrast, only the high-temperature side of the γ-relaxation was observed in the three anatomic directions in specimens with free water, which might be related to the amorphous wood cell wall coupling with the frozen free water during the quenching process. In addition, the differences in peak temperatures of the γ-relaxation among the three main directions diminished with increasing bound water.

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